mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.RingTheory.RamificationInertia.Inertia

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝¹⁹ : CommRing R
inst✝¹⁸ : CommRing S
inst✝¹⁷ : Algebra R S
p : Ideal R
q : Ideal S
inst✝¹⁶ : q.LiesOver p
inst✝¹⁵ : p.IsPrime
inst✝¹⁴ : q.IsPrime
K : Type u_4
L : Type u_5
inst✝¹³ : Field K
inst✝¹² : Field L
inst✝¹¹ : Algebra (R ⧸ p) K
inst✝¹⁰ : IsFractionRing (R ⧸ p) K
inst✝⁹ : Algebra (S ⧸ q) L
inst✝⁸ : IsFractionRing (S ⧸ q) L
inst✝⁷ : Algebra R K
inst✝⁶ : IsScalarTower R (R ⧸ p) K
inst✝⁵ : Algebra S L
inst✝⁴ : IsScalarTower S (S ⧸ q) L
inst✝³ : Algebra R L
inst✝² : IsScalarTower R S L
inst✝¹ : Algebra K L
inst✝ : IsScalarTower R K L
this : Algebra (Localization.AtPrime p) (Localization.AtPrime q) := Localization.AtPrime.algebraOfLiesOver p q
⊢ q.inertiaDeg R = Module.finrank K L

Tactic:
rw [inertiaDeg_eq p q]

Goal state after:
R : Type u_1
S : Type u_2
inst✝¹⁹ : CommRing R
inst✝¹⁸ : CommRing S
inst✝¹⁷ : Algebra R S
p : Ideal R
q : Ideal S
inst✝¹⁶ : q.LiesOver p
inst✝¹⁵ : p.IsPrime
inst✝¹⁴ : q.IsPrime
K : Type u_4
L : Type u_5
inst✝¹³ : Field K
inst✝¹² : Field L
inst✝¹¹ : Algebra (R ⧸ p) K
inst✝¹⁰ : IsFractionRing (R ⧸ p) K
inst✝⁹ : Algebra (S ⧸ q) L
inst✝⁸ : IsFractionRing (S ⧸ q) L
inst✝⁷ : Algebra R K
inst✝⁶ : IsScalarTower R (R ⧸ p) K
inst✝⁵ : Algebra S L
inst✝⁴ : IsScalarTower S (S ⧸ q) L
inst✝³ : Algebra R L
inst✝² : IsScalarTower R S L
inst✝¹ : Algebra K L
inst✝ : IsScalarTower R K L
this : Algebra (Localization.AtPrime p) (Localization.AtPrime q) := Localization.AtPrime.algebraOfLiesOver p q
⊢ Module.finrank p.ResidueField q.ResidueField = Module.finrank K L
Module: Mathlib.RingTheory.RamificationInertia.Inertia

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝¹⁹ : CommRing R
inst✝¹⁸ : CommRing S
inst✝¹⁷ : Algebra R S
p : Ideal R
q : Ideal S
inst✝¹⁶ : q.LiesOver p
inst✝¹⁵ : p.IsPrime
inst✝¹⁴ : q.IsPrime
K : Type u_4
L : Type u_5
inst✝¹³ : Field K
inst✝¹² : Field L
inst✝¹¹ : Algebra (R ⧸ p) K
inst✝¹⁰ : IsFractionRing (R ⧸ p) K
inst✝⁹ : Algebra (S ⧸ q) L
inst✝⁸ : IsFractionRing (S ⧸ q) L
inst✝⁷ : Algebra R K
inst✝⁶ : IsScalarTower R (R ⧸ p) K
inst✝⁵ : Algebra S L
inst✝⁴ : IsScalarTower S (S ⧸ q) L
inst✝³ : Algebra R L
inst✝² : IsScalarTower R S L
inst✝¹ : Algebra K L
inst✝ : IsScalarTower R K L
this : Algebra (Localization.AtPrime p) (Localization.AtPrime q) := ⋯
⊢ ∀ (x : R ⧸ p),
    ((algebraMap K L).comp (IsFractionRing.algEquivOfAlgEquiv AlgEquiv.refl).toRingEquiv.toRingHom)
        ((algebraMap (R ⧸ p) p.ResidueField) x) =
      ((IsFractionRing.algEquivOfAlgEquiv AlgEquiv.refl).toRingEquiv.toRingHom.comp
          (algebraMap p.ResidueField q.ResidueField))
        ((algebraMap (R ⧸ p) p.ResidueField) x)

Tactic:
intro x

Goal state after:
R : Type u_1
S : Type u_2
inst✝¹⁹ : CommRing R
inst✝¹⁸ : CommRing S
inst✝¹⁷ : Algebra R S
p : Ideal R
q : Ideal S
inst✝¹⁶ : q.LiesOver p
inst✝¹⁵ : p.IsPrime
inst✝¹⁴ : q.IsPrime
K : Type u_4
L : Type u_5
inst✝¹³ : Field K
inst✝¹² : Field L
inst✝¹¹ : Algebra (R ⧸ p) K
inst✝¹⁰ : IsFractionRing (R ⧸ p) K
inst✝⁹ : Algebra (S ⧸ q) L
inst✝⁸ : IsFractionRing (S ⧸ q) L
inst✝⁷ : Algebra R K
inst✝⁶ : IsScalarTower R (R ⧸ p) K
inst✝⁵ : Algebra S L
inst✝⁴ : IsScalarTower S (S ⧸ q) L
inst✝³ : Algebra R L
inst✝² : IsScalarTower R S L
inst✝¹ : Algebra K L
inst✝ : IsScalarTower R K L
this : Algebra (Localization.AtPrime p) (Localization.AtPrime q) := Localization.AtPrime.algebraOfLiesOver p q
x : R ⧸ p
⊢ ((algebraMap K L).comp (IsFractionRing.algEquivOfAlgEquiv AlgEquiv.refl).toRingEquiv.toRingHom)
      ((algebraMap (R ⧸ p) p.ResidueField) x) =
    ((IsFractionRing.algEquivOfAlgEquiv AlgEquiv.refl).toRingEquiv.toRingHom.comp
        (algebraMap p.ResidueField q.ResidueField))
      ((algebraMap (R ⧸ p) p.ResidueField) x)
Module: Mathlib.RingTheory.RamificationInertia.Inertia

Goal state before:
pp: case pos
R : Type u_1
S : Type u_2
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : Algebra R S
q : Ideal S
G : Type u_4
inst✝² : Group G
inst✝¹ : MulSemiringAction G S
inst✝ : SMulCommClass G R S
g : G
hq : q.IsPrime
p : Ideal R := under R q
⊢ (g • q).inertiaDeg R = q.inertiaDeg R

Tactic:
let f₀ := MulSemiringAction.toAlgAut G R S g

Goal state after:
case pos
R : Type u_1
S : Type u_2
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : Algebra R S
q : Ideal S
G : Type u_4
inst✝² : Group G
inst✝¹ : MulSemiringAction G S
inst✝ : SMulCommClass G R S
g : G
hq : q.IsPrime
p : Ideal R := under R q
f₀ : S ≃ₐ[R] S := (MulSemiringAction.toAlgAut G R S) g
⊢ (g • q).inertiaDeg R = q.inertiaDeg R
Module: Mathlib.RingTheory.LocalRing.Length

Goal state before:
pp: case neg
A : Type u_1
B : Type u_2
M : Type u_3
inst✝⁸ : CommRing A
inst✝⁷ : CommRing B
inst✝⁶ : IsLocalRing A
inst✝⁵ : IsLocalRing B
inst✝⁴ : Algebra A B
inst✝³ : IsLocalHom (algebraMap A B)
inst✝² : AddCommGroup M
inst✝¹ : Module A M
inst✝ : Flat A B
h : length A M = ⊤
this : length B (B ⊗[A] M) = ⊤
⊢ length B (B ⊗[A] M) = length A M * length B (B ⧸ Ideal.map (algebraMap A B) (maximalIdeal A))

Tactic:
have ne : length B (B ⧸ (maximalIdeal A).map (algebraMap A B)) ≠ 0 := by
      simpa [← pos_iff_ne_zero, length_pos_iff] using (map_maximalIdeal_lt_top (algebraMap A B)).ne

Goal state after:
case neg
A : Type u_1
B : Type u_2
M : Type u_3
inst✝⁸ : CommRing A
inst✝⁷ : CommRing B
inst✝⁶ : IsLocalRing A
inst✝⁵ : IsLocalRing B
inst✝⁴ : Algebra A B
inst✝³ : IsLocalHom (algebraMap A B)
inst✝² : AddCommGroup M
inst✝¹ : Module A M
inst✝ : Flat A B
h : length A M = ⊤
this : length B (B ⊗[A] M) = ⊤
ne : length B (B ⧸ Ideal.map (algebraMap A B) (maximalIdeal A)) ≠ 0
⊢ length B (B ⊗[A] M) = length A M * length B (B ⧸ Ideal.map (algebraMap A B) (maximalIdeal A))
Module: Mathlib.RingTheory.Ideal.IdempotentFG

Goal state before:
pp: case mp
R : Type u_1
inst✝ : CommRing R
I : Ideal R
h : I.FG
e : IsIdempotentElem I
r : R
hr : r ∈ I
hr' : ∀ n ∈ I, r * n = n
⊢ I ≤ R ∙ r

Tactic:
intro x

Goal state after:
case mp
R : Type u_1
inst✝ : CommRing R
I : Ideal R
h : I.FG
e : IsIdempotentElem I
r : R
hr : r ∈ I
hr' : ∀ n ∈ I, r * n = n
x : R
⊢ x ∈ I → x ∈ R ∙ r
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝⁶ : CommRing R
S : Type v
inst✝⁵ : CommRing S
inst✝⁴ : Algebra R S
p : Ideal R
P : Ideal S
T : Type u_2
inst✝³ : CommRing T
inst✝² : Algebra R T
inst✝¹ : Algebra S T
inst✝ : IsScalarTower R S T
Q : Ideal T
hp : p = comap f P
h : ¬sSup {n | map (algebraMap R T) p ≤ Q ^ n} = 0
n : ℕ
hn : n ∈ {n | map (algebraMap S T) P ≤ Q ^ n}
⊢ P ≤ comap (algebraMap S T) (Q ^ n)

Tactic:
rwa [← map_le_iff_le_comap]

Goal state after:
Module: Mathlib.RingTheory.Unramified.Basic

Goal state before:
pp: R : Type v
inst✝⁵ : CommRing R
A : Type u
inst✝⁴ : CommRing A
inst✝³ : Algebra R A
B : Type w
inst✝² : CommRing B
inst✝¹ : Algebra R B
I : Ideal B
inst✝ : FormallyUnramified R A
hI : I ^ 2 = ⊥
f₁ f₂ : A →ₐ[R] B
e : (Ideal.Quotient.mkₐ R I).comp f₁ = (Ideal.Quotient.mkₐ R I).comp f₂
this✝¹ : Algebra A B := f₁.toAlgebra
this✝ : IsScalarTower R A B
this : Subsingleton { f // (Ideal.Quotient.mkₐ R I).comp f = IsScalarTower.toAlgHom R A (B ⧸ I) }
⊢ f₁ = f₂

Tactic:
exact Subtype.ext_iff.mp (@Subsingleton.elim _ this ⟨f₁, rfl⟩ ⟨f₂, e.symm⟩)

Goal state after:
Module: Mathlib.RingTheory.Unramified.Basic

Goal state before:
pp: case neg
R : Type v
inst✝⁵ : CommRing R
A : Type u
inst✝⁴ : CommRing A
inst✝³ : Algebra R A
B : Type w
inst✝² : CommRing B
inst✝¹ : Algebra R B
I : Ideal B
inst✝ : FormallyUnramified R A
hI : ⨅ i, I ^ i = ⊥
g₁ g₂ : A →ₐ[R] B
H : ∀ (x : A), (Ideal.Quotient.mk I) (g₁ x) = (Ideal.Quotient.mk I) (g₂ x)
i : ℕ
hi : ¬i = 0
⊢ ∀ (x : A),
    (Ideal.Quotient.mk (Ideal.map (algebraMap B (B ⧸ I ^ i)) I)) (((Ideal.Quotient.mkₐ R (I ^ i)).comp g₁) x) =
      (Ideal.Quotient.mk (Ideal.map (algebraMap B (B ⧸ I ^ i)) I)) (((Ideal.Quotient.mkₐ R (I ^ i)).comp g₂) x)

Tactic:
intro x

Goal state after:
case neg
R : Type v
inst✝⁵ : CommRing R
A : Type u
inst✝⁴ : CommRing A
inst✝³ : Algebra R A
B : Type w
inst✝² : CommRing B
inst✝¹ : Algebra R B
I : Ideal B
inst✝ : FormallyUnramified R A
hI : ⨅ i, I ^ i = ⊥
g₁ g₂ : A →ₐ[R] B
H : ∀ (x : A), (Ideal.Quotient.mk I) (g₁ x) = (Ideal.Quotient.mk I) (g₂ x)
i : ℕ
hi : ¬i = 0
x : A
⊢ (Ideal.Quotient.mk (Ideal.map (algebraMap B (B ⧸ I ^ i)) I)) (((Ideal.Quotient.mkₐ R (I ^ i)).comp g₁) x) =
    (Ideal.Quotient.mk (Ideal.map (algebraMap B (B ⧸ I ^ i)) I)) (((Ideal.Quotient.mkₐ R (I ^ i)).comp g₂) x)
Module: Mathlib.RingTheory.Unramified.Basic

Goal state before:
pp: case neg.hf
R : Type v
inst✝⁵ : CommRing R
A : Type u
inst✝⁴ : CommRing A
inst✝³ : Algebra R A
B : Type w
inst✝² : CommRing B
inst✝¹ : Algebra R B
I : Ideal B
inst✝ : FormallyUnramified R A
hI : ⨅ i, I ^ i = ⊥
g₁ g₂ : A →ₐ[R] B
H : ∀ (x : A), (Ideal.Quotient.mk I) (g₁ x) = (Ideal.Quotient.mk I) (g₂ x)
i : ℕ
hi : ¬i = 0
x : A
⊢ Function.Surjective ⇑(Ideal.Quotient.mk (I ^ i))

Tactic:
· exact Ideal.Quotient.mk_surjective

Goal state after:
Module: Mathlib.RingTheory.Unramified.Basic

Goal state before:
pp: R : Type u_1
inst✝⁹ : CommRing R
A : Type u_2
inst✝⁸ : CommRing A
inst✝⁷ : Algebra R A
B : Type u_3
inst✝⁶ : CommRing B
inst✝⁵ : Algebra R B
inst✝⁴ : Algebra A B
inst✝³ : IsScalarTower R A B
inst✝² : FormallyUnramified R B
Q : Type u_3
inst✝¹ : CommRing Q
inst✝ : Algebra A Q
I : Ideal Q
e : I ^ 2 = ⊥
f₁ f₂ : B →ₐ[A] Q
e' : (Ideal.Quotient.mkₐ A I).comp f₁ = (Ideal.Quotient.mkₐ A I).comp f₂
this✝ : Algebra R Q := ((algebraMap A Q).comp (algebraMap R A)).toAlgebra
this : IsScalarTower R A Q := IsScalarTower.of_algebraMap_eq' rfl
⊢ ∀ (x : B),
    (Ideal.Quotient.mk I) ((AlgHom.restrictScalars R f₁) x) = (Ideal.Quotient.mk I) ((AlgHom.restrictScalars R f₂) x)

Tactic:
intro x

Goal state after:
R : Type u_1
inst✝⁹ : CommRing R
A : Type u_2
inst✝⁸ : CommRing A
inst✝⁷ : Algebra R A
B : Type u_3
inst✝⁶ : CommRing B
inst✝⁵ : Algebra R B
inst✝⁴ : Algebra A B
inst✝³ : IsScalarTower R A B
inst✝² : FormallyUnramified R B
Q : Type u_3
inst✝¹ : CommRing Q
inst✝ : Algebra A Q
I : Ideal Q
e : I ^ 2 = ⊥
f₁ f₂ : B →ₐ[A] Q
e' : (Ideal.Quotient.mkₐ A I).comp f₁ = (Ideal.Quotient.mkₐ A I).comp f₂
this✝ : Algebra R Q := ((algebraMap A Q).comp (algebraMap R A)).toAlgebra
this : IsScalarTower R A Q := IsScalarTower.of_algebraMap_eq' rfl
x : B
⊢ (Ideal.Quotient.mk I) ((AlgHom.restrictScalars R f₁) x) = (Ideal.Quotient.mk I) ((AlgHom.restrictScalars R f₂) x)
Module: Mathlib.RingTheory.QuasiFinite.Basic

Goal state before:
pp: R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁸ : CommRing R
inst✝⁷ : CommRing S
inst✝⁶ : CommRing T
inst✝⁵ : Algebra R S
inst✝⁴ : Algebra R T
inst✝³ : Algebra S T
inst✝² : IsScalarTower R S T
inst✝¹ : QuasiFinite R S
inst✝ : QuasiFinite S T
P : Ideal R
hP : P.IsPrime
this✝ : Module.Finite (P.Fiber S) (P.Fiber S ⊗[S] T)
this : Module.Finite P.ResidueField (P.Fiber S ⊗[S] T)
e : P.Fiber S ≃ₐ[S] S ⊗[R] P.ResidueField :=
  let __spread.0 := TensorProduct.comm R P.ResidueField S;
  { toEquiv := __spread.0.toEquiv, map_mul' := ⋯, map_add' := ⋯, commutes' := ⋯ }
e' : P.Fiber S ⊗[S] T ≃ₐ[R] P.Fiber T :=
  (AlgEquiv.restrictScalars R (TensorProduct.congr e AlgEquiv.refl)).trans
    ((AlgEquiv.restrictScalars R (TensorProduct.comm S (S ⊗[R] P.ResidueField) T)).trans
      ((AlgEquiv.restrictScalars R (TensorProduct.cancelBaseChange R S T T P.ResidueField)).trans
        (TensorProduct.comm R T P.ResidueField)))
e'' : P.Fiber S ⊗[S] T ≃ₐ[P.ResidueField] P.Fiber T :=
  let __spread.0 := e';
  { toEquiv := __spread.0.toEquiv, map_mul' := ⋯, map_add' := ⋯, commutes' := ⋯ }
⊢ Module.Finite P.ResidueField (P.Fiber T)

Tactic:
exact .of_surjective e''.toLinearMap e''.surjective

Goal state after:
Module: Mathlib.RingTheory.QuasiFinite.Basic

Goal state before:
pp: R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : Algebra R S
inst✝¹ : Algebra R T
inst✝ : QuasiFinite R S
f : S →ₐ[R] T
H : ∀ (x : T), ∃ s, IsUnit (f s) ∧ x * f s ∈ f.range
φ : Localization (Submonoid.comap f (IsUnit.submonoid T)) →ₐ[R] T := IsLocalization.liftAlgHom ⋯
⊢ Function.Surjective ⇑φ

Tactic:
intro x

Goal state after:
R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : Algebra R S
inst✝¹ : Algebra R T
inst✝ : QuasiFinite R S
f : S →ₐ[R] T
H : ∀ (x : T), ∃ s, IsUnit (f s) ∧ x * f s ∈ f.range
φ : Localization (Submonoid.comap f (IsUnit.submonoid T)) →ₐ[R] T := IsLocalization.liftAlgHom ⋯
x : T
⊢ ∃ a, φ a = x
Module: Mathlib.RingTheory.QuasiFinite.Basic

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : Algebra R S
inst✝¹ : IsArtinianRing R
p : PrimeSpectrum S
inst✝ : FiniteType R S
H : IsOpen {p}
this✝ : IsNoetherianRing S
this : IsJacobsonRing S
⊢ QuasiFiniteAt R p.asIdeal

Tactic:
rw [(PrimeSpectrum.isOpen_singleton_tfae_of_isNoetherian_of_isJacobsonRing p).out
    0 1 rfl rfl] at H

Goal state after:
R : Type u_1
S : Type u_2
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : Algebra R S
inst✝¹ : IsArtinianRing R
p : PrimeSpectrum S
inst✝ : FiniteType R S
H : IsClopen {p}
this✝ : IsNoetherianRing S
this : IsJacobsonRing S
⊢ QuasiFiniteAt R p.asIdeal
Module: Mathlib.RingTheory.QuasiFinite.Basic

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : Algebra R S
inst✝¹ : IsArtinianRing R
p : PrimeSpectrum S
inst✝ : FiniteType R S
H✝ : IsClopen {p}
this✝¹ : IsNoetherianRing S
this✝ : IsJacobsonRing S
e : S
he : IsIdempotentElem e
H : {p} = ↑(PrimeSpectrum.basicOpen e)
hep : e ∉ p.asIdeal
f : Localization.Away e →ₐ[S] Localization.AtPrime p.asIdeal := IsLocalization.Away.liftAlgHom e ⋯
h₁ : Set.range (PrimeSpectrum.comap (algebraMap S (Localization.Away e))) = {p}
this : Subsingleton (PrimeSpectrum (Localization.Away e))
⊢ Function.Surjective ⇑f

Tactic:
intro x

Goal state after:
R : Type u_1
S : Type u_2
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : Algebra R S
inst✝¹ : IsArtinianRing R
p : PrimeSpectrum S
inst✝ : FiniteType R S
H✝ : IsClopen {p}
this✝¹ : IsNoetherianRing S
this✝ : IsJacobsonRing S
e : S
he : IsIdempotentElem e
H : {p} = ↑(PrimeSpectrum.basicOpen e)
hep : e ∉ p.asIdeal
f : Localization.Away e →ₐ[S] Localization.AtPrime p.asIdeal := IsLocalization.Away.liftAlgHom e ⋯
h₁ : Set.range (PrimeSpectrum.comap (algebraMap S (Localization.Away e))) = {p}
this : Subsingleton (PrimeSpectrum (Localization.Away e))
x : Localization.AtPrime p.asIdeal
⊢ ∃ a, f a = x
Module: Mathlib.RingTheory.Kaehler.JacobiZariski

Goal state before:
pp: R : Type u₁
S : Type u₂
inst✝⁶ : CommRing R
inst✝⁵ : CommRing S
inst✝⁴ : Algebra R S
T : Type u₃
inst✝³ : CommRing T
inst✝² : Algebra R T
inst✝¹ : Algebra S T
inst✝ : IsScalarTower R S T
ι : Type w₁
σ : Type w₂
Q : Generators S T ι
P : Generators R S σ
⊢ Function.Surjective ⇑(Extension.Cotangent.map (Q.ofComp P).toExtensionHom)

Tactic:
intro x

Goal state after:
R : Type u₁
S : Type u₂
inst✝⁶ : CommRing R
inst✝⁵ : CommRing S
inst✝⁴ : Algebra R S
T : Type u₃
inst✝³ : CommRing T
inst✝² : Algebra R T
inst✝¹ : Algebra S T
inst✝ : IsScalarTower R S T
ι : Type w₁
σ : Type w₂
Q : Generators S T ι
P : Generators R S σ
x : Q.toExtension.Cotangent
⊢ ∃ a, (Extension.Cotangent.map (Q.ofComp P).toExtensionHom) a = x
Module: Mathlib.RingTheory.Kaehler.JacobiZariski

Goal state before:
pp: case h2
R : Type u₁
S : Type u₂
inst✝⁶ : CommRing R
inst✝⁵ : CommRing S
inst✝⁴ : Algebra R S
T : Type u₃
inst✝³ : CommRing T
inst✝² : Algebra R T
inst✝¹ : Algebra S T
inst✝ : IsScalarTower R S T
ι : Type w₁
σ : Type w₂
Q : Generators S T ι
P : Generators R S σ
⊢ ∀ (x : (Q.comp P).toExtension.Cotangent),
    (Extension.Cotangent.map (Q.ofComp P).toExtensionHom) x = 0 →
      x ∈ (LinearMap.liftBaseChange T (Extension.Cotangent.map (Q.toComp P).toExtensionHom)).range

Tactic:
intro x

Goal state after:
case h2
R : Type u₁
S : Type u₂
inst✝⁶ : CommRing R
inst✝⁵ : CommRing S
inst✝⁴ : Algebra R S
T : Type u₃
inst✝³ : CommRing T
inst✝² : Algebra R T
inst✝¹ : Algebra S T
inst✝ : IsScalarTower R S T
ι : Type w₁
σ : Type w₂
Q : Generators S T ι
P : Generators R S σ
x : (Q.comp P).toExtension.Cotangent
⊢ (Extension.Cotangent.map (Q.ofComp P).toExtensionHom) x = 0 →
    x ∈ (LinearMap.liftBaseChange T (Extension.Cotangent.map (Q.toComp P).toExtensionHom)).range
Module: Mathlib.RingTheory.Unramified.Finite

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝⁸ : CommRing R
inst✝⁷ : CommRing S
inst✝⁶ : Algebra R S
M : Type u_3
inst✝⁵ : AddCommGroup M
inst✝⁴ : Module R M
inst✝³ : Module S M
inst✝² : IsScalarTower R S M
inst✝¹ : FormallyUnramified R S
inst✝ : EssFiniteType R S
x : M
⊢ (TensorProduct.lmul' R) (elem R S) • x = x

Tactic:
rw [lmul_elem, one_smul]

Goal state after:
Module: Mathlib.RingTheory.Smooth.Basic

Goal state before:
pp: R : Type u_4
Rₘ : Type u_6
inst✝³ : CommRing R
inst✝² : CommRing Rₘ
M : Submonoid R
inst✝¹ : Algebra R Rₘ
inst✝ : IsLocalization M Rₘ
Q : Type (max u_4 u_6)
x✝¹ : CommRing Q
x✝ : Algebra R Q
I : Ideal Q
e : I ^ 2 = ⊥
f : Rₘ →ₐ[R] Q ⧸ I
⊢ ∀ (x : ↥M), IsUnit ((algebraMap R Q) ↑x)

Tactic:
intro x

Goal state after:
R : Type u_4
Rₘ : Type u_6
inst✝³ : CommRing R
inst✝² : CommRing Rₘ
M : Submonoid R
inst✝¹ : Algebra R Rₘ
inst✝ : IsLocalization M Rₘ
Q : Type (max u_4 u_6)
x✝¹ : CommRing Q
x✝ : Algebra R Q
I : Ideal Q
e : I ^ 2 = ⊥
f : Rₘ →ₐ[R] Q ⧸ I
x : ↥M
⊢ IsUnit ((algebraMap R Q) ↑x)
Module: Mathlib.RingTheory.Unramified.Locus

Goal state before:
pp: R : Type u_1
A : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
inst✝ : EssFiniteType R A
⊢ IsOpen (Module.support A Ω[A⁄R])ᶜ

Tactic:
Module.support_eq_zeroLocus

Goal state after:
R : Type u_1
A : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
inst✝ : EssFiniteType R A
⊢ IsOpen (PrimeSpectrum.zeroLocus ↑(Module.annihilator A Ω[A⁄R]))ᶜ
Module: Mathlib.RingTheory.Unramified.Field

Goal state before:
pp: case e_f
K : Type u_1
A : Type u_2
inst✝⁶ : Field K
inst✝⁵ : CommRing A
inst✝⁴ : Algebra K A
inst✝³ : FormallyUnramified K A
inst✝² : EssFiniteType K A
inst✝¹ : IsAlgClosed K
inst✝ : IsLocalRing A
this✝ : Module.Finite K A
this : IsArtinianRing A
hA : IsNilpotent (IsLocalRing.maximalIdeal A)
e : K ≃ₐ[K] A ⧸ IsLocalRing.maximalIdeal A :=
  let __spread.0 := ofId K (A ⧸ IsLocalRing.maximalIdeal A);
  let __spread.1 := Equiv.ofBijective ⇑(algebraMap K (A ⧸ IsLocalRing.maximalIdeal A)) ⋯;
  { toFun := (↑↑__spread.0.toRingHom).toFun, invFun := __spread.1.invFun, left_inv := ⋯, right_inv := ⋯, map_mul' := ⋯,
    map_add' := ⋯, commutes' := ⋯ }
e' : A ⊗[K] (A ⧸ IsLocalRing.maximalIdeal A) ≃ₐ[A] A :=
  (TensorProduct.congr AlgEquiv.refl e.symm).trans (TensorProduct.rid K A A)
f : A ⧸ IsLocalRing.maximalIdeal A →ₗ[A] A := e'.toLinearMap ∘ₗ sec K A (A ⧸ IsLocalRing.maximalIdeal A)
r : A
s : K
⊢ s • (Ideal.Quotient.mk (IsLocalRing.maximalIdeal A)) r = r • e s

Tactic:
simp [Algebra.smul_def, e, ofId, mul_comm]

Goal state after:
Module: Mathlib.RingTheory.Smooth.Kaehler

Goal state before:
pp: case refine_1.refine_1
R : Type u_1
P : Type u_2
S : Type u_3
inst✝⁶ : CommRing R
inst✝⁵ : CommRing P
inst✝⁴ : CommRing S
inst✝³ : Algebra R P
inst✝² : Algebra P S
inst✝¹ : Algebra R S
inst✝ : IsScalarTower R P S
hf' : RingHom.ker (algebraMap P S) ^ 2 = ⊥
hf : Surjective ⇑(algebraMap P S)
this : Submodule.restrictScalars R (RingHom.ker (algebraMap P S) ^ 2) ≤ (↑R ((mk P S Ω[P⁄R]) 1) ∘ₗ ↑(D R P)).ker →
  P ⧸ Submodule.restrictScalars R (RingHom.ker (algebraMap P S) ^ 2) →ₗ[R] S ⊗[P] Ω[P⁄R] :=
  (Submodule.restrictScalars R (RingHom.ker (algebraMap P S) ^ 2)).liftQ (↑R ((mk P S Ω[P⁄R]) 1) ∘ₗ ↑(D R P))
x : P
hx : x ∈ RingHom.ker (algebraMap P S) * RingHom.ker (algebraMap P S)
⊢ ∀ r ∈ RingHom.ker (algebraMap P S), ∀ n ∈ RingHom.ker (algebraMap P S), 1 ⊗ₜ[P] (D R P) (r • n) = 0

Tactic:
intro x

Goal state after:
case refine_1.refine_1
R : Type u_1
P : Type u_2
S : Type u_3
inst✝⁶ : CommRing R
inst✝⁵ : CommRing P
inst✝⁴ : CommRing S
inst✝³ : Algebra R P
inst✝² : Algebra P S
inst✝¹ : Algebra R S
inst✝ : IsScalarTower R P S
hf' : RingHom.ker (algebraMap P S) ^ 2 = ⊥
hf : Surjective ⇑(algebraMap P S)
this : Submodule.restrictScalars R (RingHom.ker (algebraMap P S) ^ 2) ≤ (↑R ((mk P S Ω[P⁄R]) 1) ∘ₗ ↑(D R P)).ker →
  P ⧸ Submodule.restrictScalars R (RingHom.ker (algebraMap P S) ^ 2) →ₗ[R] S ⊗[P] Ω[P⁄R] :=
  (Submodule.restrictScalars R (RingHom.ker (algebraMap P S) ^ 2)).liftQ (↑R ((mk P S Ω[P⁄R]) 1) ∘ₗ ↑(D R P))
x✝ : P
hx : x✝ ∈ RingHom.ker (algebraMap P S) * RingHom.ker (algebraMap P S)
x : P
⊢ x ∈ RingHom.ker (algebraMap P S) → ∀ n ∈ RingHom.ker (algebraMap P S), 1 ⊗ₜ[P] (D R P) (x • n) = 0
Module: Mathlib.RingTheory.Smooth.Kaehler

Goal state before:
pp: case refine_1.refine_2
R : Type u_1
P : Type u_2
S : Type u_3
inst✝⁶ : CommRing R
inst✝⁵ : CommRing P
inst✝⁴ : CommRing S
inst✝³ : Algebra R P
inst✝² : Algebra P S
inst✝¹ : Algebra R S
inst✝ : IsScalarTower R P S
hf' : RingHom.ker (algebraMap P S) ^ 2 = ⊥
hf : Surjective ⇑(algebraMap P S)
this : Submodule.restrictScalars R (RingHom.ker (algebraMap P S) ^ 2) ≤ (↑R ((mk P S Ω[P⁄R]) 1) ∘ₗ ↑(D R P)).ker →
  P ⧸ Submodule.restrictScalars R (RingHom.ker (algebraMap P S) ^ 2) →ₗ[R] S ⊗[P] Ω[P⁄R] :=
  (Submodule.restrictScalars R (RingHom.ker (algebraMap P S) ^ 2)).liftQ (↑R ((mk P S Ω[P⁄R]) 1) ∘ₗ ↑(D R P))
x : P
hx : x ∈ RingHom.ker (algebraMap P S) * RingHom.ker (algebraMap P S)
⊢ ∀ (x y : P), 1 ⊗ₜ[P] (D R P) x = 0 → 1 ⊗ₜ[P] (D R P) y = 0 → 1 ⊗ₜ[P] (D R P) (x + y) = 0

Tactic:
intro x

Goal state after:
case refine_1.refine_2
R : Type u_1
P : Type u_2
S : Type u_3
inst✝⁶ : CommRing R
inst✝⁵ : CommRing P
inst✝⁴ : CommRing S
inst✝³ : Algebra R P
inst✝² : Algebra P S
inst✝¹ : Algebra R S
inst✝ : IsScalarTower R P S
hf' : RingHom.ker (algebraMap P S) ^ 2 = ⊥
hf : Surjective ⇑(algebraMap P S)
this : Submodule.restrictScalars R (RingHom.ker (algebraMap P S) ^ 2) ≤ (↑R ((mk P S Ω[P⁄R]) 1) ∘ₗ ↑(D R P)).ker →
  P ⧸ Submodule.restrictScalars R (RingHom.ker (algebraMap P S) ^ 2) →ₗ[R] S ⊗[P] Ω[P⁄R] :=
  (Submodule.restrictScalars R (RingHom.ker (algebraMap P S) ^ 2)).liftQ (↑R ((mk P S Ω[P⁄R]) 1) ∘ₗ ↑(D R P))
x✝ : P
hx : x✝ ∈ RingHom.ker (algebraMap P S) * RingHom.ker (algebraMap P S)
x : P
⊢ ∀ (y : P), 1 ⊗ₜ[P] (D R P) x = 0 → 1 ⊗ₜ[P] (D R P) y = 0 → 1 ⊗ₜ[P] (D R P) (x + y) = 0
Module: Mathlib.RingTheory.Smooth.Kaehler

Goal state before:
pp: case refine_1
R : Type u_1
P : Type u_2
S : Type u_3
inst✝⁶ : CommRing R
inst✝⁵ : CommRing P
inst✝⁴ : CommRing S
inst✝³ : Algebra R P
inst✝² : Algebra P S
inst✝¹ : Algebra R S
inst✝ : IsScalarTower R P S
hf' : RingHom.ker (algebraMap P S) ^ 2 = ⊥
hf : Surjective ⇑(algebraMap P S)
P' : Type u_2 := P ⧸ RingHom.ker (algebraMap P S) ^ 2
h₁ : Surjective ⇑(algebraMap P' S)
h₂ : RingHom.ker (algebraMap P' S) ^ 2 = ⊥
e₁ : (RingHom.ker (algebraMap P S)).Cotangent ≃ₗ[P] ↥(RingHom.ker (algebraMap P' S)) :=
  (RingHom.ker (algebraMap P S)).cotangentEquivIdeal ≪≫ₗ
    LinearEquiv.restrictScalars P
      (LinearEquiv.ofEq (RingHom.ker (IsScalarTower.toAlgHom R P S).toRingHom).cotangentIdeal
        (RingHom.ker (IsScalarTower.toAlgHom R P S).kerSquareLift.toRingHom) ⋯)
e₂ : S ⊗[P'] Ω[P'⁄R] ≃ₗ[P] S ⊗[P] Ω[P⁄R] := LinearEquiv.restrictScalars P (tensorKaehlerQuotKerSqEquiv R P S)
H : kerCotangentToTensor R P S = ↑e₂ ∘ₗ ↑P (kerToTensor R P' S) ∘ₗ ↑e₁
x✝ : { l // l ∘ₗ kerCotangentToTensor R P S = LinearMap.id }
l : S ⊗[P] Ω[P⁄R] →ₗ[P] (RingHom.ker (algebraMap P S)).Cotangent
hl : l ∘ₗ kerCotangentToTensor R P S = LinearMap.id
y : S ⊗[P'] Ω[P'⁄R]
x : P
⊢ (↑(↑e₁ ∘ₗ l ∘ₗ ↑e₂)).toFun (x • y) =
    (RingHom.id (P ⧸ RingHom.ker (algebraMap P S) ^ 2)) ((algebraMap P (P ⧸ RingHom.ker (algebraMap P S) ^ 2)) x) •
      (↑(↑e₁ ∘ₗ l ∘ₗ ↑e₂)).toFun y

Tactic:
exact (e₁.toLinearMap ∘ₗ l ∘ₗ e₂.toLinearMap).map_smul x y

Goal state after:
Module: Mathlib.RingTheory.Unramified.Field

Goal state before:
pp: K : Type u_1
A : Type u_2
inst✝⁶ : Field K
inst✝⁵ : CommRing A
inst✝⁴ : Algebra K A
inst✝³ : FormallyUnramified K A
inst✝² : EssFiniteType K A
inst✝¹ : IsAlgClosed K
inst✝ : IsLocalRing A
⊢ IsLocalRing.maximalIdeal A ≤ ⊥

Tactic:
intro x

Goal state after:
K : Type u_1
A : Type u_2
inst✝⁶ : Field K
inst✝⁵ : CommRing A
inst✝⁴ : Algebra K A
inst✝³ : FormallyUnramified K A
inst✝² : EssFiniteType K A
inst✝¹ : IsAlgClosed K
inst✝ : IsLocalRing A
x : A
⊢ x ∈ IsLocalRing.maximalIdeal A → x ∈ ⊥